I building a wood oven using the basic directions? I'm cutting a few corner and making use of some materials i already owned. So after pouring the foundation i then following the cinder block design for the stand, i have topped the stand w/ 5/8" steel instead of pouring a foundation on top of the stand. This is the stuff that's used on roadways. Anyway, my question is can I go lay my firebricks right on top of the metal? I planned on using the sand, firebrick, water mixture directly on top of the metal. or i could lay down a few inches of gravel first. what do u guys think? My friend has a mold to pour my own oven that will sit on top of the firebricks. thanks, aaron